(1) Field of the Invention.
This invention relates to earth working and more particularly agricultural cultivators for cultivating row crops planted in skip row cultivation so that selected rows may be cultivated or not cultivated.
(2) Description of the Prior Art.
In agricultural practices often it is desirable to plant row crops in a skip row configuration with two rows planted and one row skipped. When the crop is cultivated, the cultivators normally move up one set of rows and down the next cultivating the field. This causes the same plow upon the cultivator implement to be above a planted row when going in one direction and a skip or blank row when going in the other. It is desirable to have the blank row cultivated but it is, of course, necessary to transfer the plow into a non-cultivating position when moving in the opposite direction. This situation is illustrated in FIG. 1 as will be explained more particularly later on.
Prior to my invention cultivators to solve this problem were commercially upon the market which would have cultivator shanks mounted upon an eccentric tool bar. Then at the end of moving in one direction the tool bar would be rotated sufficiently to bring one set of plows down and the other set of plows up. However, this required a rigid tool bar. In modern agriculture today often a very long tool bar is used. For maneuverability in transportation of the equipment from one location to another it is desirable to have these long tool bars fold. I.E., there is a central portion of the tool bar with wings on each side which fold upward. Therefore, having a rotating eccentric tool bar was not compatible with folding wings and the farmer could not have such a system with a folding wing tool bar.
Before filing this application the applicant caused search to be made in the United States Patent and Trademark Office. That search revealed the following U.S. Pat. Nos.:
Bergeland 1,711,485 PA1 Bickerton 1,808,759 PA1 Legendre 2,053,618 PA1 McGee 3,058,243 PA1 Haverdink 3,967,684
MCGEE discloses an earthworking apparatus with a plurality of chisel teeth. Each of the chisel teeth are slideable up and down on the tool bar which is in cylindrical form. The back of each shank is in the form of a rack with teeth thereon. A pinion mounted upon a common shaft engages the rack so that the shanks may be raised and lowered.
HAVERDINK shows the folding wing cultivator as discussed above.
BICKERTON discloses a planting apparatus where the opening discs for the planter are each adjustable by an individual hydraulic cylinder so that each of the discs runs the same uniform depth for planting the seed.
The other two patents do not seem as pertinent as those specifically discussed above.